An evaluation kit for a microorganism detecting device includes an immobilized microorganism. A manufacturing method for an evaluation kit for a microorganism detecting device includes immobilizing a microorganism. An evaluating method for the microorganism detecting device includes detecting an immobilized microorganism by the microorganism detecting device. The immobilized microorganisms may be dispersed in a solvent. The solvent may be water. The immobilized microorganisms may be immobilized with an aldehyde. The aldehyde may be formaldehyde. The immobilized microorganisms emit, for example, fluorescent light.