A machine base supports at least one of a clamping unit and an injection unit of an injection molding machine from below. The machine base includes an upper frame extended horizontally and configured to support at least one of the clamping unit and the injection unit. The upper frame has a hollow member and a plate member having a concave cross-section, attached to an upper surface of the hollow member. The plate member and the hollow member are formed with a through hole penetrating from an upper surface of the plate member to a hollow portion in the hollow member.

Provided is a base (30) used in an injection molding machine. The base (30) for an injection molding machine includes, two side frames (40) extending parallel with the axis of a drive actuator (16). Each of the side frames (40) includes a lower flange (44) supported by a bed (11), an upper flange (45) disposed parallel with the lower flange (44), at least two webs (46) connecting the upper flange (45) and the lower flange (44), and a web reinforcing member (47) fixed to the webs (46) while penetrating the webs (46).

An injection molding machine according to the present invention includes a base mounted on a mounting surface with a support interposed therebetween with a distance D1 and a distance D2 to the mounting surface, a plurality of measurement units attached to the base so as to measure distances respectively to the mounting surface, and a horizontal degree calculation unit for calculating a horizontal degree of the base on a basis of the distances measured by the plurality of measurement units.