To provide a fixing jig capable of easily attaching or detaching a split model to or from a tray by easily and accurately performing a work of regulation, measurement or the like in a state in which a positional relation of the split model is accurately maintained.

The fixing jig for the split model comprises a tray and a plurality of bases each detachably mounted to the tray to hold the split model. The jig mounts the split model on the tray and performs the regulation, the measurement or the like of the model. The tray 100 has grooves 110 to be engaged with parts 205 of the bases 201, 202 and 203, and channels 120 formed at an equivalent pitch (p) at both sides of opposed inside walls of the grooves 110. The bases 201, 202 and 203 each has an engaging pat 220 to be engaged with the channel 120 when the part 205 is engaged with the groove 110 of the tray 100.