Abstract: A horizontal supporter for scaffolds is disclosed. The horizontal supporter is configured such that, when a pressing piece is moved upward in order to unlock a locking piece, the pressing piece and the locking piece are caught by each other due to engagement between a catching recess and a latching projection, whereby the pressing piece remains moved upward, wherein, even when the elasticity of an elastic body is reduced due to repetitive use of the horizontal supporter or even when a gap is formed between the related parts due to wear of the related parts, it is possible to prevent the pressing piece from moving downward due to the weight of the pressing piece, whereby it is possible to eliminate trouble in use and to reduce financial loss due to a reduction in the lifespan of the horizontal supporter.