A turbocharger comprising: a housing having a hollow shape; a rotary shaft rotatably supported by the housing; a turbine integrally disposed in a first end portion in a first axial direction in the rotary shaft; and a compressor disposed in a second end portion in the first axial direction in the rotary shaft, and the second end portion is connected to a side of an attachment surface of the compressor impeller, wherein a screw portion and a column portion are disposed on the rotary shaft along the first axial direction in the second end portion of the rotary shaft, wherein a screw hole into which the screw portion is screwed and a fitting hole into which the column portion is fitted are disposed in the compressor impeller along a second axial direction of the compressor impeller, wherein a first axial length dimension of the column portion of the rotary shaft in the first axial direction is set to be longer than a second axial length dimension of the screw portion of the rotary shaft, and a third axial length dimension (LBi) of the fitting hole of the compressor impeller in the second direction is set to be longer than a fourth axial length dimension of the screw hole of the compressor impeller in the second direction, and the second axial length dimension and the fourth length dimension are set to be the same as each other, and wherein the column portion is disposed on a side of the second end portion of the rotary shaft from the screw portion, and the screw hole is disposed on a side of the attachment surface of the compressor impeller from the fitting hole, wherein an outer diameter dimension (dB) of the column portion and an inner diameter dimension of the fitting hole are substantially the same as each other so that both of these can be fitted to each other, and wherein an outer diameter dimension (dB) of the column portion is set to be smaller than an inner diameter dimension (dA) of the screw hole, and wherein the column portion is fitted into the fitting hole before the screw portion is screwed into the screw hole. a housing having a hollow shape; a rotary shaft rotatably supported by the housing; a turbine integrally disposed in a first end portion in a first axial direction in the rotary shaft; and a compressor disposed in a second end portion in the first axial direction in the rotary shaft, and the second end portion is connected to a side of an attachment surface of the compressor impeller, wherein a screw portion and a column portion are disposed on the rotary shaft along the first axial direction in the second end portion of the rotary shaft, wherein a screw hole into which the screw portion is screwed and a fitting hole into which the column portion is fitted are disposed in the compressor impeller along a second axial direction of the compressor impeller, wherein a first axial length dimension of the column portion of the rotary shaft in the first axial direction is set to be longer than a second axial length dimension of the screw portion of the rotary shaft, and a third axial length dimension (LBi) of the fitting hole of the compressor impeller in the second direction is set to be longer than a fourth axial length dimension of the screw hole of the compressor impeller in the second direction, and the second axial length dimension and the fourth length dimension are set to be the same as each other, and wherein the column portion is disposed on a side of the second end portion of the rotary shaft from the screw portion, and the screw hole is disposed on a side of the attachment surface of the compressor impeller from the fitting hole, wherein an outer diameter dimension (dB) of the column portion and an inner diameter dimension of the fitting hole are substantially the same as each other so that both of these can be fitted to each other, and wherein an outer diameter dimension (dB) of the column portion is set to be smaller than an inner diameter dimension (dA) of the screw hole, and wherein the column portion is fitted into the fitting hole before the screw portion is screwed into the screw hole.