Variations in the quality of starting end parts of cladding layers are reduced. An aspect of the present disclosure is a method for forming a cladding layer in which a cladding layer is formed by starting to supply a metal powder onto a base material by changing a supply instruction to an on-state, and irradiating the metal powder with a laser beam according to a laser output pattern corresponding to the supply instruction. The method includes, before forming the cladding layer, acquiring a fluidity of the metal powder, and changing the laser output pattern according to the acquired fluidity.