A pattern drawing device is provided with: a first cylindrical lens on which a beam from a light source device is incident and which has an anisotropic refractive power for converging, in a sub-scanning direction orthogonal to a main scanning direction, the beam traveling toward a reflection surface of a polygon mirror; an fθ lens system for causing the beam having been deflected by the reflection surface of the polygon mirror to be incident thereon, and for condensing the beam as a spot light on a surface of an object to be irradiated; and a second cylindrical lens having an anisotropic refractive power for converging, in the sub-scanning direction, the beam traveling toward the surface after being emitted from the fθ lens system.