To provide a decoration device for a concrete wall, which enables various patterns to be simply and easily applied to the concrete wall under a soft state of mortar by precedently applying the mortar onto the wall.

A frame body 2 capable of making a traverse motion on the wall 10 is provided; an ascendable/descendable base 15 is provided for the frame body 2; and a stamping implement 40 equipped with a pattern body 42 is attached to the base 15 in such a manner as to be movable forward/backward. A mark for each section is put on a wire 11 for hoisting/lowering the base 15.