A viable particle counter for counting viable particles contained in a dialysis fluid, the viable particle counter comprising: a light emitting means configured to radiate a light with a predetermined wavelength toward the dialysis fluid containing a detection target; an autofluorescence selecting optical means configured to reduce transmission of a Raman-scattered light emitted from the dialysis fluid out of lights emitted due to an interaction of the detection target or the dialysis fluid with the light radiated from the light emitting means and to transmit an autofluorescence emitted from the detection target; a viable particle determining means configured to determine whether or not the detection target contained in the dialysis fluid is a viable particle, based on a light obtained after the Raman-scattered light is reduced by the autofluorescence selecting optical means; and a liquid distributing means configured to distribute the dialysis fluid for blood dialysis or blood filtration, wherein the light emitting means radiates the light with the predetermined wavelength that causes the autofluorescence and the Raman-scattered light which are emitted after the irradiation to be different in peak wavelength, and wherein, based on the autofluorescence out of the lights emitted due to an interaction between the detection target contained in the dialysis fluid and the light radiated from the light emitting means, the viable particle determining means determines whether or not the detection target contained in the dialysis fluid is the viable particle, characterized by a liquid dividing means configured to make part of the dialysis fluid distributed by the liquid distributing means branch off as the dialysis fluid containing the detection target before the dialysis fluid is administered to a human body, wherein the light emitting means radiates the light with the predetermined wavelength toward the dialysis fluid made to branch off by the liquid dividing means. a light emitting means configured to radiate a light with a predetermined wavelength toward the dialysis fluid containing a detection target; an autofluorescence selecting optical means configured to reduce transmission of a Raman-scattered light emitted from the dialysis fluid out of lights emitted due to an interaction of the detection target or the dialysis fluid with the light radiated from the light emitting means and to transmit an autofluorescence emitted from the detection target; a viable particle determining means configured to determine whether or not the detection target contained in the dialysis fluid is a viable particle, based on a light obtained after the Raman-scattered light is reduced by the autofluorescence selecting optical means; and a liquid distributing means configured to distribute the dialysis fluid for blood dialysis or blood filtration, wherein the light emitting means radiates the light with the predetermined wavelength that causes the autofluorescence and the Raman-scattered light which are emitted after the irradiation to be different in peak wavelength, and wherein, based on the autofluorescence out of the lights emitted due to an interaction between the detection target contained in the dialysis fluid and the light radiated from the light emitting means, the viable particle determining means determines whether or not the detection target contained in the dialysis fluid is the viable particle, characterized by a liquid dividing means configured to make part of the dialysis fluid distributed by the liquid distributing means branch off as the dialysis fluid containing the detection target before the dialysis fluid is administered to a human body, wherein the light emitting means radiates the light with the predetermined wavelength toward the dialysis fluid made to branch off by the liquid dividing means.