Abstract: A recoater of an additive manufacturing apparatus includes a powder retention section that defines a retention space in which a powder material is retained, and a slit part that has a slit inlet that receives the powder material retained and a slit outlet through which the powder material is discharged. The slit part includes a plate member fixed to the powder retention section by surface contact. A pair of slit inner wall surfaces that is connected to the slit outlet and faces each other is formed within a plate thickness of the plate member.

Abstract: For a slit outlet width d and a slit inclination angle ?, the following relations (1) and (2) are satisfied: d?0.0024×(??75°)2+4.5, and d?Lc?2h/tan ?, wherein ? [°] is a slit inclination angle being an acute angle formed by at least one of slit inner wall surfaces and a slit outlet surface of a slit part, d [mm] is a slit outlet width being a width of a slit outlet formed by the pair of slit inner wall surfaces in a moving direction, h [mm] is a slit height being a shortest distance between the slit outlet and a slit inlet, and Lc [mm] is a retention section width being a width of a powder retention section in the moving direction at a position where the powder retention section is connected to the slit part.