PURPOSE: To provide a cell phase adjustment circuit able to adjust cell phases of plural cell flows into an optional cell phase.

CONSTITUTION: A main write control section, or a sub write control section, a read control section and an FIFO are provided to each of plural inputted cell flows. A main write control section 101 generates a write pulse for an FIFO 107, a write enable signal 2G and a read enable signal 2H1 from the input cell phase. A sub write control section 102 generates a write pulse for an FIFO 108, a read enable signal 2H2 from the input cell phase and the write enable signal 2G. Thus, when the cell phase of each inputted cell flow is spread optionally with a prescribed width to be specified and the relation of the order of cells between the cell flows is reserved to require the adjustment of the cell phase in the adjustment of the cell phase of plural cell flows and even when the cell is read in an optional cell phase, the order of cells is reserved.