A tank support structure includes an inclined surface (21) formed on a side surface section of a housing section (2), a plurality of support base sections (22) arranged on the inclined surface (21), and a plurality of support blocks (4) arranged in a bottom surface section (31) of a tank (3) including a portion opposed to the inclined surface (21) and arranged on the support base sections (22). Support block bottom surfaces (41) arranged on the support base sections (22) of the support blocks (4) and support surfaces (22a) of the support base sections (22) that support the support blocks (4) have surfaces parallel to a plane (S) including a segment (CC′) connecting two contact points (a first contact point (C) and a second contact point (C′)) with the tank (3) in each of the support blocks (4) and a straight line (Lf) passing a fixed point (F) of the tank (3) and parallel to the segment (CC′).