A multi-branch net box trap comprising a plurality of symmetrically arranged individual net box trap branches radially extending from a common centre, wherein each net box trap branch comprises a trap body comprising in said trap body a trap mouth, followed by a narrowing, a trap box and a closure, two wings each with a turned-back distal end part on respective lateral sides of said trap mouth and a fish court in front of said trap mouth between said wings, wherein between the trap bodies of the branches of the net box trap, there are guide fences running in a direction originating from the common centre, and the trap mouths of the branches of the net box trap are facing the common centre, and a common fish court of the branches is formed between the turned-back distal end parts of the wings of the trap mouths of the branches, and said common fish court is divided by internal guide fences originating from the common centre into equal sections, wherein the trap body of each branch of the net box trap, when viewed from above, has basically the shape of an isosceles triangle, the sides of which are formed by a net, which is from below and above enveloped by a net from the tip of the branch to the trap mouth, forming said trap box, where the trap mouth comprises a narrowing with convergent cross section opening into the trap box located behind said narrowing, wherein at the ends of the sides of the branches are wings, where distal end parts of said wings are turned back towards the trap mouth at an angle, and where the fish court is formed in front of the trap mouth between said wings, wherein the three net box trap branches arranged symmetrically around a common centre, at the points where the distal end parts of said wings continuing from the sides of the branches are turned back towards a trap mouth, are connected respectively at the top and at the bottom with connection cords to the points where distal end parts of the wings continuing from the sides of the adjacent net box trap branch are turned back towards a trap mouth, thereby forming three input apertures respectively for the common fish court around the common centre between said turned-back points the wings of said adjacent net box trap branches, wherein said common fish court is divided around the common centre with three internal guide fences into three sections, where each respective internal guide fence is directed from the common centre between the wings of the respective branch towards the trap mouth, and where between each of the two branches to the central part of the upper and lower connecting cord respectively are connected the ends of upper and lower edges of the guide fence, said guide fence extending away from the common fish court in a direction originating from the common centre. wherein between the trap bodies of the branches of the net box trap, there are guide fences running in a direction originating from the common centre, and the trap mouths of the branches of the net box trap are facing the common centre, and a common fish court of the branches is formed between the turned-back distal end parts of the wings of the trap mouths of the branches, and said common fish court is divided by internal guide fences originating from the common centre into equal sections, wherein the trap body of each branch of the net box trap, when viewed from above, has basically the shape of an isosceles triangle, the sides of which are formed by a net, which is from below and above enveloped by a net from the tip of the branch to the trap mouth, forming said trap box, where the trap mouth comprises a narrowing with convergent cross section opening into the trap box located behind said narrowing, wherein at the ends of the sides of the branches are wings, where distal end parts of said wings are turned back towards the trap mouth at an angle, and where the fish court is formed in front of the trap mouth between said wings, wherein the three net box trap branches arranged symmetrically around a common centre, at the points where the distal end parts of said wings continuing from the sides of the branches are turned back towards a trap mouth, are connected respectively at the top and at the bottom with connection cords to the points where distal end parts of the wings continuing from the sides of the adjacent net box trap branch are turned back towards a trap mouth, thereby forming three input apertures respectively for the common fish court around the common centre between said turned-back points the wings of said adjacent net box trap branches, wherein said common fish court is divided around the common centre with three internal guide fences into three sections, where each respective internal guide fence is directed from the common centre between the wings of the respective branch towards the trap mouth, and where between each of the two branches to the central part of the upper and lower connecting cord respectively are connected the ends of upper and lower edges of the guide fence, said guide fence extending away from the common fish court in a direction originating from the common centre.