PROBLEM TO BE SOLVED: To provide an energy-conserving and highly workable cutting device for a concrete wall surface, the cutting device being of a simple configuration that is not massive, offering ease of transportation and handling, allowing a cutter body to be supported horizontally for certain, enabling cutting work to be completed in a short period of time by smoothly moving the cutter body by human power because a load on a rotary blade is small during cutting, capable of cutting an entire periphery at almost a uniform depth with only a small amount of corner portions that are left uncut, and facilitating removal of a concrete basin after cutting.SOLUTION: A cutting device for a concrete wall surface includes a frame part fixed on a periphery of an opening of a concrete basin, and a cutter moving mechanism disposed on the frame part for moving a cutter body along an inner wall of the concrete basin on a horizontal plane. The cutter moving mechanism includes a cutter holding part that holds a cutter bod
