To provide a slope angle regulator for a placing machine which can simply set the slope angle of a placing base, has good workability and can always obtain a predetermined set slope angle without unevenness.

The placing machine 1 is used to charge a concrete in a form W and to mold a molding. The placing machine 1 comprises the placing base 2 rotatably provided between the substantially horizontal placing position and the working position B inclined at the predetermined angle by a suitable actuator at the base 2 for placing the form W, and a detector for detecting the slope angle of the base 2 at the position B to adjustably set the slope angle of the base 2. The detector is a limit switch provided movably at the fixed side, and a dog brought into contact with the switch is provided at the rotary side.