diff --git a/tests/cypress/integration/actions_tasks/case_100_settings_default_number_of_points_in_polygon_approximation.js b/tests/cypress/integration/actions_tasks/case_100_settings_default_number_of_points_in_polygon_approximation.js
new file mode 100644
index 00000000..819cb4a9
--- /dev/null
+++ b/tests/cypress/integration/actions_tasks/case_100_settings_default_number_of_points_in_polygon_approximation.js
@@ -0,0 +1,64 @@
+// Copyright (C) 2021 Intel Corporation
+//
+// SPDX-License-Identifier: MIT
+
+/// <reference types="cypress" />
+
+import { taskName } from '../../support/const';
+
+context('Settings. Default number of points in polygon approximation.', () => {
+    const caseId = '100';
+
+    function testOpenSettingsWorkspace() {
+        cy.document().then((doc) => {
+            const settingsModal = Array.from(doc.querySelectorAll('.cvat-settings-modal'));
+            if (settingsModal.length === 0) {
+                cy.openSettings();
+                cy.contains('[role="tab"]', 'Workspace').click();
+            }
+        });
+    }
+
+    function testCheckSliderAttrValuenow(expectedValue) {
+        testOpenSettingsWorkspace();
+        cy.get('.cvat-workspace-settings-approx-poly-threshold').find('[role="slider"]').then((slider) => {
+            expect(slider.attr('aria-valuenow')).to.be.equal(expectedValue);
+        });
+    }
+
+    function generateString(countPointsToMove) {
+        let action = '';
+        for (let i = 0; i < countPointsToMove; i++) {
+            action += '{rightarrow}';
+        }
+        return action;
+    }
+
+    before(() => {
+        cy.openTaskJob(taskName);
+    });
+
+    describe(`Testing case "${caseId}"`, () => {
+        it('Change the setting value for "Default number of points in polygon approximation".', () => {
+            testOpenSettingsWorkspace();
+            cy.get('.cvat-workspace-settings-approx-poly-threshold')
+                .find('[role="slider"]')
+                .type(generateString(4))
+                .then((slider) => {
+                    const sliderAttrValueNow = slider.attr('aria-valuenow');
+                    const sliderAttrValuemin = slider.attr('aria-valuemin');
+                    const sliderAttrValuemax = slider.attr('aria-valuemax');
+                    cy.saveSettings();
+                    cy.closeNotification('.cvat-notification-notice-save-settings-success');
+                    cy.closeSettings();
+                    cy.reload();
+                    cy.closeModalUnsupportedPlatform(); // If the Firefox browser closes the modal window after reload
+                    testCheckSliderAttrValuenow(sliderAttrValueNow);
+                    cy.contains('strong', 'less').click();
+                    testCheckSliderAttrValuenow(sliderAttrValuemin);
+                    cy.contains('strong', 'more').click();
+                    testCheckSliderAttrValuenow(sliderAttrValuemax);
+                });
+        });
+    });
+});