A sensor for blood component analysis that can correct the effect of a hematocrit easily is provided. The sensor includes an analysis portion including a working electrode, a counter electrode, and a reagent portion. The reagent portion includes an oxidoreductase that reacts with the blood component and a mediator, and the blood component is measured by causing a redox reaction between the blood component and the oxidoreductase in the presence of the mediator and detecting a redox current generated by the redox reaction by the working electrode and the counter electrode. In this sensor, the reagent portion further includes a hemolyzing agent (e.g., sodium cholate) for hemolyzing an erythrocyte, and when detecting the redox current, the erythrocyte is hemolyzed with the hemolyzing agent so as to cause hemoglobin released to an outside of the erythrocyte to react with the mediator and a current generated by this reaction also is detected to correct an effect of a hematocrit.