In a device for mass spectrometry, an analyte contained in a sample is desorbed from a surface of the device by irradiating the sample in contact with the surface with measurement light. The device includes a micro-structure having a plurality of metal bodies on a surface of a substrate, and the plurality of metal bodies have sizes that can excite localized plasmons by irradiation with the measurement light. Further, the device includes an initiator fixed at least to a part of a surface of the micro-structure.