Provided is a microneedle containing a bioactive substance, one or more amino acids selected from the group consisting of arginine and histidine, and an acid having a melting point of 40 DEG C or higher.本發明係提供含有生理活性物質、選自精胺酸及組胺酸所成群中之一種以上的胺基酸、以及熔點為40℃以上的酸之微刺針。