An aerosol housing mechanism comprising: - an outer tubular portion (2a, 10a) attached to an opening side of a container body that stores emission target content and ejection gas; - a central tubular portion (2b, 10b) formed on an inner side of the outer tubular portion (2a, 10a) so as to store at least a lower-side portion of a stem that operates with a content emission operation in an interlocked manner; - an annular ceiling portion (2c, 10c) formed between an upper end portion of the outer tubular portion (2a, 10a) and an upper end portion of the central tubular portion (2b, 10b); and - a rib-shaped portion (2h, 10h) formed between the outer tubular portion (2a, 10a) and the central tubular portion (2b, 10b) to enhance a structural strength, wherein - entireties of the outer tubular portion (2a, 10a), the central tubular portion (2b, 10b), the annular ceiling portion (2c, 10c), and the rib-shaped portion (2h, 10h) are integrally molded using a synthetic resin, and - a vertical groove-shaped portion (2f, 10f) for passage of content is formed in a portion of an inner peripheral surface of the central tubular portion (2b, 10b), characterised in that - a vertical concave portion is formed in a portion of an outer peripheral surface of the central tubular portion (2b, 10b), which is on a rear side of an inner peripheral surface portion in which the vertical groove-shaped portion (2f, 10f) is not formed, wherein the rib-shaped portion (2h, 10h) is formed between an inner peripheral surface of the outer tubular portion (2a, 10a) and a rear-side outer peripheral surface portion of the vertical groove-shaped portion (2f, 10f), in which the vertical concave portions are not present. - an outer tubular portion (2a, 10a) attached to an opening side of a container body that stores emission target content and ejection gas; - a central tubular portion (2b, 10b) formed on an inner side of the outer tubular portion (2a, 10a) so as to store at least a lower-side portion of a stem that operates with a content emission operation in an interlocked manner; - an annular ceiling portion (2c, 10c) formed between an upper end portion of the outer tubular portion (2a, 10a) and an upper end portion of the central tubular portion (2b, 10b); and - a rib-shaped portion (2h, 10h) formed between the outer tubular portion (2a, 10a) and the central tubular portion (2b, 10b) to enhance a structural strength, wherein - entireties of the outer tubular portion (2a, 10a), the central tubular portion (2b, 10b), the annular ceiling portion (2c, 10c), and the rib-shaped portion (2h, 10h) are integrally molded using a synthetic resin, and - a vertical groove-shaped portion (2f, 10f) for passage of content is formed in a portion of an inner peripheral surface of the central tubular portion (2b, 10b), characterised in that - a vertical concave portion is formed in a portion of an outer peripheral surface of the central tubular portion (2b, 10b), which is on a rear side of an inner peripheral surface portion in which the vertical groove-shaped portion (2f, 10f) is not formed, wherein the rib-shaped portion (2h, 10h) is formed between an inner peripheral surface of the outer tubular portion (2a, 10a) and a rear-side outer peripheral surface portion of the vertical groove-shaped portion (2f, 10f), in which the vertical concave portions are not present.