An objective of the present invention is to provide stable antibody-containing formulations which are suitable for subcutaneous administration and in which aggregation formation is suppressed during long-term storage. The present inventors discovered that a significant stabilization effect was achieved by using an acidic amino acid, aspartic acid or glutamic acid as a counter ion species in histidine buffer or tris(hydroxymethyl)aminomethane, specifically by using histidine-aspartate buffer or histidine-glutamate buffer, or tris(hydroxymethyl)aminomethane-aspartate or tris(hydroxymethyl)aminomethane-glutamate as a buffer. The present inventors also discovered that a significant stabilization effect was achieved by using an acidic amino acid, aspartic acid or glutamic acid, as a counter ion species to a basic amino acid such as arginine, specifically by using arginine-aspartate or arginine-glutamate.
