The purpose of the present invention is to improve evaluation accuracy of a photographed image when an event occurs. An image evaluation method according to the present invention includes steps, which are carried out by a server, for: storing, in a plurality of storage units, organism images each corresponding to a mode of an organism and outbreak environment information indicating the range of environment information suited for a mode of an organism； receiving a photographed image transmitted from a portable terminal； receiving environment information measured by a sensor terminal from the sensor terminal； retrieving organism images similar to the received photographed image among a plurality of organism images and assigning scores to names each related to the mode of an organism corresponding to the retrieved organism image； extracting names each related to the mode of an organism associated with outbreak environment information including the environment information received from the sensor terminal； assigning a weight to the scores of the extracted names； and transmitting a name, having the highest score among the plurality of scores as an evaluation result name, to the portable terminal that has transmitted the photographed image.
