An apparatus for sorting cells includes a cell alignment portion applying a process to a cell-suspending fluid with a great number of cells and arraying the cells with a spacing between each cell, a cell information detecting portion detecting information on the cells, a cell sorting portion for sorting the cells based upon the information detected by the cell information detecting portion, a first passage of the cell alignment portion so as to let the cell-suspending fluid flow, and a second passage of the cell alignment portion, intersecting with the first passage so as to communicate therewith, letting a splitting fluid flow so as to split the flow of the cell-suspending fluid in the first passage and forming a great number of small cell-containing liquid drops.