It is intended to provide a blood test apparatus whereby the vicinity of a site to be punctured for collecting the blood can be negatively pressurized and the negative pressurization can be conducted at an appropriate time without resorting to a special operation, thereby facilitating a blood test. More specifically speaking, a blood test apparatus which comprises: a housing having an opening: a puncture means located in the opening a first sensing means whereby the contact of the front face of the opening with a site to be punctured is detected a negative pressurization means whereby the inside of the opening is negatively pressurized a blood sensor whereby the blood, that flows out from the punctured site having been punctured by the puncture means after negatively pressurizing the inside of the opening by the negative pressurization means, is collected and a measurement circuit whereby a signal obtained from the blood sensor analyzing components in the blood is measured, wherein the negative pressurization means starts up when the first sensing means detects the contact of the front face of the opening with the site to be punctured.
