PROBLEM TO BE SOLVED: To provide cell culture of high quality comprising no impurity components resulting from a producing process, which may provide an obstacle for clinical application and a producing method thereof.SOLUTION: In the present invention, there are provided: a producing method of sheet shape cell culture including (i) a process of inoculating cells on a cultivation substrate coated with serum and (ii) a process of generating the sheet shape cell culture by culturing the cells the sheet shape cell culture produced with the method the cultivation substrate coated with serum utilized in the method a producing method and producing kit of the cultivation substrate and a method for suppressing production of inflammatory cytokine in the cell culture, which method includes (i) a process of inoculating cells on the cultivation substrate coated with serum and (ii) a process of generating cell culture by cultivating the cells with a serum-free medium.
