The present invention addresses the problem of providing a slime-removing tablet for intermittent or continuous use in running water, wherein the tablet for slime removal and slime prevention is strong and capable of increasing the initial concentration of a bactericidal component eluted, and then eluting further concentrations of the bactericidal component that are equal to or more than a prescribed concentration over an extended period. This slime-removing tablet for intermittent or continuous use in running water has a shape including (A) and/or (B), (A) being a concave provided to the centre part of the top surface of the tablet and/or the centre part of the bottom surface of the tablet, and (B) being a through-hole from the centre part of the top surface of the tablet to the centre part of the bottom surface of the tablet. The initial concentration of a bactericidal component eluted is high and then further concentrations of the bactericidal component that are equal to or more than a prescribed concentration are eluted over an extended period.
