A noninvasive blood component measuring device configured so as to resolve the variance of measuring results depend on the fixing position to the living body. Concretely, a non-invasive blood component measuring device comprising a light source section for illuminating a living body which includes a blood vessel, an imaging section for imaging the living body illuminated by the light source, and a controller is disclosed. The controller includes a memory under control of a processor. The memory stores instructions enabling the processor to carry out following operations: calculating a blood component concentration based on a blood vessel in a living body image obtained by the imaging section imaging a living body determining the position of the blood vessel in the living body image preparing at least a first luminance distribution which is distributed along the blood vessel based on the position of the blood vessel obtaining an index which reflects the amount of blood contained in the peripheral tissue of the blood vessel based on the first luminance distribution and correcting the blood component concentration based on the index. Non-invasive blood component measuring method and a computer program product capable of achieving above mentioned function are also disclosed.
