Arabinan endo-1,5-ñ-L-arabinanase (, endo-1,5-ñ-L-arabinanase, endo-ñ-1,5-arabanase, endo-arabanase, 1,5-ñ-L-arabinan 1,5-ñ-L-arabinanohydrolase) is an enzyme with systematic name 5-ñ-L-arabinan 5-alpha-L-arabinanohydrolase. This enzyme catalyses the following chemical reaction
This enzyme is most active on linear 1,5-ñ-L-arabinan.