To provide a fluid suction/exhaust device capable of lowering noise due to arrangement at unequal intervals in spite of its uneven-interval arrangement of blades.

In this fluid suction/exhaust device having blades 24a and an impeller 24 having blade grooves 24b arranged between the blades 24a in its circumference, sucked fluid is discharged by rotation of the impeller 24. An adjacent angle Θ of the blade grooves 24b is set according to a predetermined periodic function and arranged in the circumference direction. Desirably, the periodic function is defined as Θ(no)=360/[N+Kcos{2π/N/(no-1)}] when a predetermined blade groove Θ1 is used as a reference, the blades 24 are numbered with (no), and the adjacent angle matching the blade 24a (no) with the number (no) is represented by Θ(no). In this expression, N represents the total number of blades, and K represents a coefficient varying the degree of influence of a trigonometric function cos.