The present invention causes residual stress, which may be generated in a metal shaped object (MO), to be small. A metal shaping device includes an irradiation device (13, 13A). The irradiation device (13, 13A), which is configured to irradiate a powder bed (PB) containing a metal powder with laser light (L), is able to be switched between (i) a focused state in which a beam spot diameter (D1) of laser light (L) on a surface of the powder bed (PB) has a first value and (ii) a defocused state in which the beam spot diameter (D2) of the laser light (L) on the surface of the powder bed (PB) has a second value which is larger than the first value.