A cloud streaming server test apparatus, comprising: virtual client modules (250, 252, 254) configured to receive test results corresponding to a predetermined test script key input from cloud streaming servers (130, 140, 150) and to create test result videos; a comparison unit; and a test control unit configured to determine, based on a comparison result, if two compared images are not identical with each other that at least one of the cloud streaming servers (130, 140, 150) has a failure, wherein the comparison unit is configured to request, under the control of the test control unit, a delivery of the test result videos created at each of the virtual client modules (250, 252, 254), to create at least one masked video by masking a part having animation in the test result videos, to create test result images by capturing the masked videos, to set a reference result image, to compare the created test result images with the reference result image by comparing a test result image, created by capturing a masked video corresponding to a reference server which is one of the cloud streaming servers (130, 140, 150) with test result images created by capturing test result videos corresponding to other cloud streaming servers (140, 150), and to output a comparison result to the test control unit, after a steady state condition is satisfied, wherein the steady state condition is an elapse condition of a predetermined time which is determined according to the predetermined test script key input, wherein the test control unit is further configured to change the reference server when a change condition for the reference server is satisfied, and if a number of cloud streaming servers determined as having failures before changing the reference server is greater, by a predetermined number or more, than a number of cloud streaming servers determined as having failures after changing the reference server, the test control unit is further configured to determine that there is a failure in the reference server before said server is changed. virtual client modules (250, 252, 254) configured to receive test results corresponding to a predetermined test script key input from cloud streaming servers (130, 140, 150) and to create test result videos; a comparison unit; and a test control unit configured to determine, based on a comparison result, if two compared images are not identical with each other that at least one of the cloud streaming servers (130, 140, 150) has a failure, wherein the comparison unit is configured to request, under the control of the test control unit, a delivery of the test result videos created at each of the virtual client modules (250, 252, 254), to create at least one masked video by masking a part having animation in the test result videos, to create test result images by capturing the masked videos, to set a reference result image, to compare the created test result images with the reference result image by comparing a test result image, created by capturing a masked video corresponding to a reference server which is one of the cloud streaming servers (130, 140, 150) with test result images created by capturing test result videos corresponding to other cloud streaming servers (140, 150), and to output a comparison result to the test control unit, after a steady state condition is satisfied, wherein the steady state condition is an elapse condition of a predetermined time which is determined according to the predetermined test script key input, wherein the test control unit is further configured to change the reference server when a change condition for the reference server is satisfied, and if a number of cloud streaming servers determined as having failures before changing the reference server is greater, by a predetermined number or more, than a number of cloud streaming servers determined as having failures after changing the reference server, the test control unit is further configured to determine that there is a failure in the reference server before said server is changed.