To apply tension to a plurality of chain spans at the same time by a simple composition.

The tensioner device 340 has a pair of tensioner arms 308a and 308b respectively having pivoting ends 330a and 330b capable of rotating around fixed pins 306a and 306b, link ends 332a and 332b, and shoes 312a and 312b forming chain sliding faces 310a and 310b, a pair of link members 318a and 318b having first ends pivotally attached to each link end of each tensioner arm 308a and 308b, and a housing 320 for receiving a piston 316 having a tip in contact with a pin 316 pivotally joining second ends of the link members. By rotating each link member around the first end via the pin 316 by the piston tip, each tensioner arm is rotated to a side of a chain center line, and tension is evenly applied to each chain span.