To provide an eaves gutter cutting tool being easily operated without causing a step on a cut face of an eaves gutter.

A member 6 to be guided is composed of an upper member 31 and a lower member 32, and a base plate 5 of an electric saw 4 is nipped and held by the upper member 31 and the lower member 32 and is integrally connected with them. The lower member 32 is constituted in such a way that a pair of belt-like plates 35 are formed by being separated from each other linearly and one end parts of both of belt-like plates opposing to each other are bent downward at a right angle and are fixed on rectangular body parts 36 to be guided which are parallel with the belt-like plates 35 and cross them orthogonally. The base plate 5 and the lower member 32 are integrally and mutually connected and fixed by adjusting a position of a rotary blade 8 of the electric saw 4 to position it in a substantially central part of the body part 36 to be guided, inserting the upper member 31 into an insertion part 34, and fixing it by a fastener 34a. Guide parts 45 for guiding the member 6 to be guided fixed onto the base plate 5 of the electric saw 4 along a guide member 3 are attached to lower end faces of the pair of belt-like plates 35, respectively.