PURPOSE: To automate operations from charging to discharging of treated parts by providing an automatic locker operating when a basket is housed in a supporter in a basket locker for an automatic dip coater treating a large number of small-size parts.

CONSTITUTION: A dip coating process is automated by using a system in which parts to be treated, housed in a basket 19, are treated according to a preset program. A supporter 18 is provided at the lower end of a rotary shaft 7, having a U-shaped groove 17 provided in a mutually facing manner. The basket metal fitting 20 of the basket 19 is guided to the U-shaped groove of the supporter 18, and then clamped by a gas stopping pin 22 to a gas locker. The locker 23 consists of a rock pin 25 with the same groove 24 as the U-shaped groove, a spring 26 to push up the pin 25 within the supporter all the time, and the second cylinder 27 to push down the pin.