To provide a rotary cam type pressing device capable of improving production speed and lessening frequency of maintenance due to wear.

The rotary cam type pressing device includes a rotary cam 11 rotatably attached to the lower holder 12 on the lower side, a pad 13 and a working cam 16 for pressing a workpiece to the rotary cam 11, and an antirotation block 20 slidably provided under a block part 11b provided in the rotary cam 11 and for preventing the rotation of the rotary cam 11, wherein a surface 23a slightly inclined with resect to the sliding direction is formed in the part opposite to the block part 11b of the antirotation block 20, and a surface 22a corresponding thereto is also formed in the block part 11b.