A tester apparatus capable of obtaining a forming limit diagram pertaining to a sample having a high degree of precision includes a fixing jig and a mobile jig installed at an upper side of the fixing jig so as to enable a vertical movement. The mobile jig may be configured to fix the sample in cooperation with the fixing jig, and a driving apparatus disposed at a lower side of the fixing jig may be configured to drive the vertical movement of the mobile jig. An interlocking apparatus provided in between the mobile jig and the driving apparatus may be configured to deliver a driving force of the driving apparatus to the mobile jig.