An application roller comprises inclined sections which monotonously extend from central parts of peaks to the bottom of grooves. Hence, a liquid developer (a carrier liquid and toner particles) remaining on wall surfaces of the grooves of the application roller and the like without moving to a developer roller from the application roller, due to its own gravity, moves to the bottom of the grooves while applied upon the developer roller, and stays at inner bottom parts of the grooves. This effectively prevents air from getting trapped in the grooves during carrying of the liquid developer to the grooves, and hence, permits carrying of an appropriate amount of the liquid developer.