To provide a midair swimming body which can move in the air according to the operation command floating in the air.

A fish-like midair swimming body 1 has a balloon 111 of the head part 11 thereof sealed with a He gas and a balloon 131 of the body part 13 thereof sealed with a He gas for floating itself. The fish-like midair swimming body 1 has the head part 11, the body part 13 (or tail handle) and the tail fin 15 of the fish and all of them are linked with link parts 31 and 32. The body part 13 and the tail fin 15 are driven with two servomechanisms 51 and 52. A computer for control carried on the body part 13 varies the pulse width of PWM of the two servomechanisms 51 and 52 to change the rotating range of the servomechanisms 51 and 52. This causes a change in the operation start timing (phase difference τ) to differentiate the motion pattern and moving speed of the body part 13 and the tail fin 15. Thus, the fish-like midair swimming body 1 moves in the air according to the rotation of the body part 13 and the tail fin 15.