PURPOSE: To remove a developer liquid remaining on a developer head when development is completed by providing the device with a development effecting part of specified form, suction pump and air release valve.

CONSTITUTION: When an air release valve 37 is opened, the surface of the developer liquid filling in buffer rooms 25a, 25b rapidly sinks. The developer remaining in slit windows 22a, 22b and groove 41a is removed by sucking effect of the pump 31. The upper surface of the developer effecting part 41 comes near the window 22b, the distance from the upper surface of the base body 21 decreases. Thus, the developer remaining between the development effecting part 41 and the recording sheet P is collected to the downstream side of the carrying direction of the recording sheet, near the end of window 22b of the developing part 41. The developer remaining is efficienctly carried to a sucking and drying groove 23. Thereby, the amt. of recording sheet P to be carried to remove the developer remaining is decreased and the time and amt. of recording sheet P for this operation can be decreased.