A separation membrane module (1, 1A, 1B) comprising: a tubular housing; and tubular separation membranes that are arranged in the housing in a longitudinal direction of the housing, the separation membrane module (1, 1A, 1B) being configured for flowing a fluid to be processed through a fluid-processing chamber inside the housing in a direction from one end toward another end of the chamber, the tubular separation membranes being configured to retrieve the fluid that has permeated through the tubular separation membranes and an end portion of each tubular separation membrane being supported by a support member that is installed in the housing such that the support member extends to cross the housing, wherein the separation membrane module further comprises: a collection chamber that is defined in the support member and that is in communication with an inside of each of the tubular separation membranes; a retrieving member (5n, 6n) that retrieves the fluid in the collection chamber to outside of the housing; a backpressure chamber that is defined between the support member and an end portion of the housing; and a communication portion that communicates an inside of the backpressure chamber to the fluid-processing chamber, characterized by further comprising end tubes which are coupled with lower ends of the tubular separation membranes, wherein the support member is a support box including a box body that has a top, a bottom, and a side surface and has the collection chamber therein, wherein insertion holes in which lower ends of the end tubes, that are coupled with the tubular separation membranes are inserted, are formed on the top of the support box, and joints between the end tubes and the tubular separation membranes are sealed by using gaskets, O-rings, or thermal shrink tubes. a tubular housing; and tubular separation membranes that are arranged in the housing in a longitudinal direction of the housing, the separation membrane module (1, 1A, 1B) being configured for flowing a fluid to be processed through a fluid-processing chamber inside the housing in a direction from one end toward another end of the chamber, the tubular separation membranes being configured to retrieve the fluid that has permeated through the tubular separation membranes and an end portion of each tubular separation membrane being supported by a support member that is installed in the housing such that the support member extends to cross the housing, wherein the separation membrane module further comprises: a collection chamber that is defined in the support member and that is in communication with an inside of each of the tubular separation membranes; a retrieving member (5n, 6n) that retrieves the fluid in the collection chamber to outside of the housing; a backpressure chamber that is defined between the support member and an end portion of the housing; and a communication portion that communicates an inside of the backpressure chamber to the fluid-processing chamber, characterized by further comprising end tubes which are coupled with lower ends of the tubular separation membranes, wherein the support member is a support box including a box body that has a top, a bottom, and a side surface and has the collection chamber therein, wherein insertion holes in which lower ends of the end tubes, that are coupled with the tubular separation membranes are inserted, are formed on the top of the support box, and joints between the end tubes and the tubular separation membranes are sealed by using gaskets, O-rings, or thermal shrink tubes. a collection chamber that is defined in the support member and that is in communication with an inside of each of the tubular separation membranes; a retrieving member (5n, 6n) that retrieves the fluid in the collection chamber to outside of the housing; a backpressure chamber that is defined between the support member and an end portion of the housing; and a communication portion that communicates an inside of the backpressure chamber to the fluid-processing chamber, characterized by further comprising end tubes which are coupled with lower ends of the tubular separation membranes, wherein the support member is a support box including a box body that has a top, a bottom, and a side surface and has the collection chamber therein, wherein insertion holes in which lower ends of the end tubes, that are coupled with the tubular separation membranes are inserted, are formed on the top of the support box, and joints between the end tubes and the tubular separation membranes are sealed by using gaskets, O-rings, or thermal shrink tubes.