PROBLEM TO BE SOLVED: To provide a cap of a two-agent discharge device which can prevent unintended discharging of an agent and, while being used as a container for mixing a first agent and a second agent, can easily prepare and apply a two-agent type hair treatment agent.SOLUTION: A cap 1 of a two-agent discharge device comprises two aerosol containers 31 and a discharge head 33 fitted to the upper parts thereof. The discharge head 33 has an outside cover 35, a discharge operation part 38, and a nozzle part 39. The cap can be detachably fitted to the discharge head 33 of the two-agent discharge device 3 for discharging a first agent and a second agent from the nozzle part 39 by operating the discharge operation part 38. The cap 1 has a body cover part 12 covering an upper end part of the discharge head 33 including the discharge operation part 38 portion, and a nozzle cover part 13 projecting from the body cover part 12 and covering the nozzle part 39. A portion covering the upper end part of the discharge head 33 of the body cover part 12 forms a recess having a long shape along a connection direction of the two aerosol containers 31.SELECTED DRAWING: Figure 1【課題】意図しない剤の吐出を防止できるとともに、第１剤と第２剤とを混合する容器として用いて、二剤式の毛髪処理剤の調製や塗布作業を簡便に行うことができる二剤吐出装置のキャップの提供。【解決手段】本発明の二剤吐出装置のキャップ１は、二つのエアゾール容器３１と、それらの上部に取り付けられる吐出ヘッド３３とを備え、吐出ヘッド３３が、外側カバー３５、吐出操作部３８及びノズル部３９を有し、吐出操作部３８の操作により、第１剤及び第２剤がノズル部３９から吐出される二剤吐出装置３の吐出ヘッド３３に脱着自在に取り付け可能である。キャップ１は、吐出操作部３８部分を含む吐出ヘッド３３の上端部を覆う本体カバー部１２と、本体カバー部１２から突出し且つノズル部３９を覆うノズルカバー部１３とを有し、本体カバー部１２の吐出ヘッド３３の上端部を覆う部分が二つのエアゾール容器３１の連結方向に沿って長い形状の凹部を形成している。【選択図】図１
