Provided is a device and a method, said device enabling the measurement of both of blood glucose level and hemoglobin A1c level, being small-sized and thus portable, allowing the measurement of a small amount of a specimen and, therefore, being usable in POC. The device for measuring the blood glucose level and hemoglobin A1c level of a blood specimen comprises: a test piece-mounting section (1) for detachably mounting test pieces (200) on which the blood specimen is to be spotted; a light-emitting section (2) for emitting light for irradiating the test pieces (200); a light-receiving section (3) for receiving reflected lights from the test pieces (200); and an operating section (4) for calculating the blood glucose level and hemoglobin A1c level of the blood specimen on the basis of photometric values obtained from the light-receiving section (3). As a test piece (200) for measuring the blood glucose level of the blood specimen, a test piece (A), which carries a composition (a) reacting with glucose and showing color development, is mounted. As a test piece (200) for measuring the hemoglobin A1c level of the blood specimen, a test piece (B), which carries a composition (b) reacting with glycated hemoglobin and showing color development, is mounted.