To provide a small-sized heating/drying device which can be used suitably for in-line treatment for assembling semiconductor device.

This heating/drying device is provided with a heater block 3, which is formed in a prism-like shape and supported rotatably about its longitudinal center axis. A transfer arm puts works to be heated or dried in the grooves of the block 3 from transfer rails 17a, and at the same time, takes out heated or dried works from the block 3 and puts the works taken-out on the rails 17. The works put in the grooves of the block 3 are retained by means of a lid 10, which can be opened by means of tension spring hinges 11. A heater 5 incorporated in the block 3 heats and dries the works put in the grooves.