Electron tube, imaging device and electromagnetic wave detection device

In an electron tube (1), the meta-surface (S) emits an electron in response to an incidence of the electromagnetic wave. The first and second electrodes (81, 82) are spaced away from each other, and apply potentials different from each other to the meta-surface (S). A holder (30) is disposed in the housing (10) and holds the electron emitter (20). A first conductive line (83) of the meta-surface (S) is electrically connected to the first electrode (81). A second conductive line (84) of the meta-surface (S) is spaced away from the first conductive line (83), and is electrically connected to the second electrode (82). The first conductive line (83) extends from the first electrode (81) to the second conductive line (84). The second conductive line (84) extends from the second electrode (82) to the first conductive line (83).