A method for manufacturing an electron source comprising steps of: preparing a first member provided with a columnar portion made of a first material having an electron emission characteristic and with an end face; preparing a second member (2,12) made of a second material having a higher work function and a lower strength than the first material, wherein the second material is glassy carbon, and comprising a tubular portion in which a hole (3,13) extending in a direction from one end face (2c,12a) toward the other end face (2d, 12b) is formed; pressing the columnar portion into the hole (3,13) in the second member (2,12); and cutting a protruding portion of the first member, so that the entire side surface of the columnar portion is covered by the tubular portion, wherein the end face of the columnar portion and the one end face of the second member (2,12) form a flat surface; wherein, in a cross-section orthogonal to a longitudinal direction of the columnar portion, the columnar portion has a cross-sectional shape that is dissimilar to a cross-sectional shape of the hole (3,13) of the second member (2,12), and in the step, by pressing the columnar portion into the hole (3,13), a portion of a side surface of the columnar portion scrapes an inner surface of the tubular portion and bites into the second member (2,12), thereby fixing the columnar portion to the second member (2,12). preparing a first member provided with a columnar portion made of a first material having an electron emission characteristic and with an end face; preparing a second member (2,12) made of a second material having a higher work function and a lower strength than the first material, wherein the second material is glassy carbon, and comprising a tubular portion in which a hole (3,13) extending in a direction from one end face (2c,12a) toward the other end face (2d, 12b) is formed; pressing the columnar portion into the hole (3,13) in the second member (2,12); and cutting a protruding portion of the first member, so that the entire side surface of the columnar portion is covered by the tubular portion, wherein the end face of the columnar portion and the one end face of the second member (2,12) form a flat surface; wherein, in a cross-section orthogonal to a longitudinal direction of the columnar portion, the columnar portion has a cross-sectional shape that is dissimilar to a cross-sectional shape of the hole (3,13) of the second member (2,12), and in the step, by pressing the columnar portion into the hole (3,13), a portion of a side surface of the columnar portion scrapes an inner surface of the tubular portion and bites into the second member (2,12), thereby fixing the columnar portion to the second member (2,12). wherein the end face of the columnar portion and the one end face of the second member (2,12) form a flat surface; wherein, in a cross-section orthogonal to a longitudinal direction of the columnar portion, the columnar portion has a cross-sectional shape that is dissimilar to a cross-sectional shape of the hole (3,13) of the second member (2,12), and in the step, by pressing the columnar portion into the hole (3,13), a portion of a side surface of the columnar portion scrapes an inner surface of the tubular portion and bites into the second member (2,12), thereby fixing the columnar portion to the second member (2,12).