A three-dimensional shaping device includes a laser irradiation unit (10), a shroud (20), and a protection member (14). The laser irradiation unit includes an optical system (12). The shroud (20) includes an inside space (S0) that extends from one end opening portion (202) to another end opening portion (206). The protection member (14) is formed of a transparent material and is arranged at the one end opening portion (202) of the shroud (20) and causes a laser light emitted from the laser irradiation unit (10) to be transmitted therethrough so that a three-dimensional shaped object is fabricated in a shaping area by sintering or melting and solidifying a powder. The shroud (20) further includes a side wall portion (22) that demarcates a first inside space (S1) and a second inside space (S2), an air supply port (210), an exhaust port (220), and ventilation members (212, 214).