A test method of a battery cell is provided. In a placement step, a device places, in a test tray, a magazine in which a plurality of battery cells are arrayed and stored. The test tray includes a pressurization mechanism configured to press, in an array direction, the plurality of battery cells. In a pressurization step, the plurality of battery cells is pressed by the pressurization mechanism. In a transfer step, the test tray storing the magazine is transferred between a preparation area where the magazine is placed in the test tray in the placement step and a test area. In a test step, in the test area, a test concerning charge/discharge of the plurality of battery cells is performed in the test area in a state in which the plurality of battery cells are pressurized by the pressurization mechanism.