Provided are an electron emitting body having a high electron beam density and an X-ray emitting device embedding the electron emitting body. The electron emitting body has a substrate, the surface of which forms a concave surface, and a carbon film comprising a large number of projections made of carbon and expanded two-dimensionally. The carbon crystal grows such that first a swell portion (22) gradually becomes larger and then a needle-like portion (23) grows from the head of the swell portion (22). The needle-like portion (23) has a graphene sheet obliquely wound therearound in a multi-layer fashion and has a hollow inside. The axis of a carbon projection (21) thus formed is substantially orthogonal to a line tangent to the concave surface (11), so that the axes of a plurality of the carbon projections (21) intersect with each other at the focal point (F) of the concave surface (11).