The present invention aims at providing a well unit to be used in fabricating an apparatus whereby movements of cells based on their own actions can be accurately and easily detected, in detecting the chemotaxis of cells due to a chemotactic factor or the inhibition of the chemotaxis of cells by an inhibitor. Accordingly, the present invention provides a well unit to be used in an apparatus for detecting chemotaxis of cells and separating cells characterized in that a plural number of wells, in which a liquid sample can be held in a resting state, are connected to each other via a channel, the channel is provided with a bank, and, in the upper part of the bank, barriers constituting one or more grooves having a width and/or a depth fit for the diameter or deformability of cells are provided or a plane is provided so as to give a gap having a depth fit for the diameter or deformability of cells between the plane and the glass substrate. |