To provide a coaxial resonator device equipped with a characteristics adjusting screw to meet the requirement for higher performance, which is simple in component shapes, involves a smaller number of components and costs less.

A coaxial resonator device comprises: a resonator array in which a plurality of coaxial resonators 4 are arrayed in parallel to one another; a casing member 31 fitted to the resonator array and having a planar part crossing the coaxial resonators 4 in the axial direction; and characteristics adjusting screws 5 so adapted to the planar part of the casing member 31 as to protrude from the planar part of the casing member 31 toward the resonator array. The characteristics adjusting screws 5 are tapping screws screwed into the planar part of the casing member 31 when fitted into under holes 6 formed on the planar part of the casing member 31 in advance.