Abstract: The present invention provides a system for providing a T cell product, including a T cell master cell bank and/or a T cell working cell bank.

Abstract: To enable stable supply of differentiated T cells, the present invention provides a method for producing, or a method for expansion culture, or a kit for expansion culture of a CD3-positive cell in which T cell marker CD3 is expressed on the cell membrane.

Abstract: Provided is a method for producing a CD4/CD8 double positive cell, including the following steps: step 1: separating, from a cell population containing a hematopoietic progenitor cell, a cell expressing one or more kinds of molecules selected from the first group consisting of CD24, CD62L, CD90, CD143, CD263, Notch3, CD32, CD39, CD49a, CD164, CD317, CD200, CD218a, CD7, CD144, CD56, CD226, CD262 and CD325, and/or a cell not expressing one or more kinds of molecules selected from the second group consisting of CD49f, CD51, CD102, CD42b, CD61, CD62P, CD69, CD102 and CD156c, and step 2: differentiating the cell separated in step 1 into a CD4/CD8 double positive cell.