A spectrometer includes a light detection element provided with a light passing part, a first light detection part, and a second light detection part, a support fixed to the light detection element such that a space is formed, a first reflection part provided in the support and configured to reflect light passing through the light passing part in the space, a second reflection part provided in the light detection element and configured to reflect the light reflected by the first reflection part in the space, and a dispersive part provided in the support and configured to disperse and reflect the light reflected by the second reflection part to the first light detection part in the space. A plurality of second light detection parts is disposed in a region surrounding the second reflection part.