To provide a flower holder, a drip pan, a flower module and an adjuster tool that are optimal for flower arrangement decoration.

The flower module (M) comprises the flower holders (H) to which cut flowers are inserted for arrangement, the drip pans (D) which hold the flower holders, supports (S) which guide the drip pans in the vertical direction, frames (F), and the like. The flower holders have each a case (121) in which water can be stored and flowers are inserted. The flower holder is formed on the bottom end of a case and is equipped with a water flow inlet (122) through which water is introduced, when water is fed from outside, and with a check valve (123) that is arranged above the water flow inlet (122), permits the water to flow the inlet into the case and inhibits the water from flowing out toward the water flow inlet side.