Provided is a load cell attachment structure for an injection molding machine, whereby attachment/detachment of a load cell in an injection device can be facilitated, and the resin pressure acting on a screw can be precisely detected. An injection device (3) is provided with a heating tube attachment bracket (13) for holding a heating cylinder (14), a plurality of nut bodies (18) fixed to the heating tube attachment bracket (13), threaded shafts (38) screwed into the nut bodies (18), a linear motion body (31) for retaining the threaded shafts (38) to allow rotation thereof, a screw (15) inserted in the heating cylinder (14) so as to be able to rotate and travel forward and backward, a rotating connector (34) for connecting the screw (15) and the linear motion body (31), a measuring electric servo motor (36) for driving rotation of the screw (15), an injection electric servo motor (40) for driving rotation of the threaded shafts (38), and a load cell (19) for detecting a resin pressure acting on the screw (15). The load cell (19) is disposed between the heating tube attachment bracket (13) and at least one of the plurality of nut bodies (18).