To provide a support device easily turning equipment to an optional direction and stably fixing the equipment.

A first gear part 32a is formed on one end of a second spindle 32. The first gear part 32a is stored in a second storage part 12d and a fourth storage part 13d where gear-like projections are formed for locking the first gear part 32a. A tightening degree of a first frame 12 and a second frame 13 is adjusted by a tightening knob 11 to rotate an arm 10 to a direction f or to fix the arm. A second gear part 32c is formed on the other end of the second spindle 32, and the second gear part 32c and a third gear part 20b formed on an upper surface of a body 20a of a base part 20 are engaged with each other. A tightening degree of the second gear part 32c and the third gear part 20b is adjusted by a rotatable knob 33 to rotate the arm 10 to the direction g or to fix the arm.