The present invention relates to a novel compound represented by the following formula (1) or a pharmaceutically acceptable salt thereof. wherein each symbol is as defined in the specification. According to the present invention, an activated blood coagulation factor X inhibitor, and a novel anticoagulant for an extracorporeal blood circuit can be provided. Moreover, the present invention relates to an anticoagulant for an extracorporeal blood circuit, which contains, as an active ingredient, an FXa selective low-molecular weight FXa inhibitor having a short half-life in blood.
