To improve test efficiency of a tire test by shortening a stand-by time required for replacement of tires.

A tire test machine 1 according to the present invention comprises: a pair of spindles 2 that holds a tire rotatably around a shaft facing a horizontal direction; carrying-in means 4 that carries in the tire to one rim 3; and tire attaching/detaching means 6 that fixedly holds the tire between rims 3 by bringing the other rim 3 close to one rim 3, and detaches the tire from the rims 3 by separating the other rim 3 from one rim 3. When detaching the tire, in a state where the tire is demounted from one rim 3, the tire attaching/detaching means 6 is configured to horizontally move the other spindle 2 so as to separate the other spindle 2 from one spindle 2 with the tire attached to the other spindle 2, and the tire attaching/detaching means 6 is provided with carrying-out means 5 for carrying out the tire in a state of the tire being separated from one rim 3 and being attached to the other rim 3.