According to one embodiment, a measuring cell includes a main cell member, and a mixture supported by or held in the main cell member. The mixture includes a nonaqueous solvent-including medium and one or more enzyme bodies. The one or more enzyme bodies are selected from the group including an enzyme, a first composite including an enzyme and a molecular aggregate that includes a dispersant, a microcapsule including an enzyme-including core and a shell covering the core, a cell including an enzyme, a microorganism including an enzyme, and a second composite including an enzyme and a support immobilizing the enzyme.