To provide a fixation device configured to more strongly maintain a fixed state and miniaturize a fixation part.

The fixation device includes: a pair of tubular arm parts 15b provided with a short cylindrical base part 12a at one end, provided with a universal joint part 14a at the other end 13a, and piled up with each other and arranged turnably at the short cylindrical base part; and an operation part 17 of a fixation part 16 capable of fixing the turning operation of the tubular arm parts. At the contact surface parts of the short cylindrical base parts, engaging parts capable of being engaged with each other and regulating mutual turning of the tubular arm parts are formed respectively. By the fixing operation of the operation part, a pair of pressurizing blocks inside the tubular arm parts abutt on an inclined part, a pair of rods inside the tubular arm parts are separated from each other, the universal joint parts 32b are fixed respectively, the engaging parts are engaged with each other, and thus the pair of tubular arm parts are fixed. By the releasing operation of the operation part, the fixation of the universal joint part is released, engagement is also released, and the turning of the pair of tubular arm parts is made possible.