A urine flow meter comprising: a urine collection part configured to collect urine to urinate and provided at one end-side of a urine flow passage tube through which the urine to be collected by the urine collection part is to flow; a water wheel unit provided at the other end-side of the urine flow passage tube and having a water wheel configured to rotate by flowing of the urine to flow from the urine flow passage tube and having a plurality of blades, and a rotation detection means configured to detect rotation of the blades, wherein a shape of an end portion of the urine flow passage tube by which the urine is to be hit against the water wheel is formed so that one side of a tip-side of the urine flow passage tube is obliquely cut to form a nozzle part having an opening formed on a sidewall surface of the tip-side of the urine flow passage tube, wherein a guide extending in a longitudinal direction of the nozzle part is provided in a urine flow passage between the opening of the nozzle part and an opposite sidewall surface thereto and a tip of the guide is disposed to extend to a tip-side region of the urine flow passage tube and is obliquely formed to have a tapered shape, and wherein the urine to flow through the urine flow passage tube is to be introduced into the nozzle part, is to be guided by the guide, is to be introduced into the tip of the guide, is to be collected at the tip-side of the guide and is to flow down to tip-sides of the blades to rotate the water wheel, the rotation of the water wheel is to be detected by the rotation detection means and a urine flow rate is to be detected on the basis of the rotation detection information. a urine collection part configured to collect urine to urinate and provided at one end-side of a urine flow passage tube through which the urine to be collected by the urine collection part is to flow; a water wheel unit provided at the other end-side of the urine flow passage tube and having a water wheel configured to rotate by flowing of the urine to flow from the urine flow passage tube and having a plurality of blades, and a rotation detection means configured to detect rotation of the blades, wherein a shape of an end portion of the urine flow passage tube by which the urine is to be hit against the water wheel is formed so that one side of a tip-side of the urine flow passage tube is obliquely cut to form a nozzle part having an opening formed on a sidewall surface of the tip-side of the urine flow passage tube, wherein a guide extending in a longitudinal direction of the nozzle part is provided in a urine flow passage between the opening of the nozzle part and an opposite sidewall surface thereto and a tip of the guide is disposed to extend to a tip-side region of the urine flow passage tube and is obliquely formed to have a tapered shape, and wherein the urine to flow through the urine flow passage tube is to be introduced into the nozzle part, is to be guided by the guide, is to be introduced into the tip of the guide, is to be collected at the tip-side of the guide and is to flow down to tip-sides of the blades to rotate the water wheel, the rotation of the water wheel is to be detected by the rotation detection means and a urine flow rate is to be detected on the basis of the rotation detection information.