Measuring apparatus and measuring method

A measuring apparatus comprising:

• a light source;
• a beam splitter that splits light from the light source into first light and second light, the second light being used to irradiate a sample containing particles treated as measuring objects;
• a first imaging device that images a first interference pattern formed by multiplexing third light, which has been generated by irradiating the particles with the second light, and the first light;
• a second imaging device that images a second interference pattern formed by the third light;
• and
• an arithmetic device that compares a composite image with a calculated image, the composite image being created by using a first interference image picked up by the first imaging device and a second interference image picked up by the second imaging device, the calculated image being obtained by combining single particle interference images, each of which is expected to be obtained by the first imaging device in a case where a particle is present alone in the sample.