A fiber guide to be applied to a pneumatic spinning device, the fiber guide comprising: a main body having a front end surface and a rear end surface in a direction of an axis; and a fiber passage formed in the main body and connecting an inlet formed on the front end surface and an outlet formed on the rear end surface, wherein the inlet is a long hole extending in a predetermined direction at a position different from the axis, in the main body, when a first region located on one side and a second region located on another side with respect to a virtual plane including the axis and equally dividing the inlet are defined, the fiber passage includes: a first surface disposed mostly in the first region and extending to be inclined from the inlet toward the outlet; and a second surface disposed mostly in the second region, the second surface is inclined to be away from the first surface as approaching the outlet, the second surface is inclined at 5 degrees or more with respect to the axis, and in the outlet, an area of a first portion included in the first region is smaller than an area of a second portion included in the second region, characterized in that: the second surface extends to be inclined from the inlet toward the outlet, the first surface is inclined at 5 degrees or less with respect to the axis, the second surface is inclined at 30 degrees or less with respect to the axis, and wherein, between the first surface and the second surface, a twisted surface having a shape twisted with respect to an extending direction of the axis is formed, and the first surface and the second surface are connected by the twisted surface. a main body having a front end surface and a rear end surface in a direction of an axis; and a fiber passage formed in the main body and connecting an inlet formed on the front end surface and an outlet formed on the rear end surface, wherein the inlet is a long hole extending in a predetermined direction at a position different from the axis, in the main body, when a first region located on one side and a second region located on another side with respect to a virtual plane including the axis and equally dividing the inlet are defined, the fiber passage includes: a first surface disposed mostly in the first region and extending to be inclined from the inlet toward the outlet; and a second surface disposed mostly in the second region, the second surface is inclined to be away from the first surface as approaching the outlet, the second surface is inclined at 5 degrees or more with respect to the axis, and in the outlet, an area of a first portion included in the first region is smaller than an area of a second portion included in the second region, characterized in that: the second surface extends to be inclined from the inlet toward the outlet, the first surface is inclined at 5 degrees or less with respect to the axis, the second surface is inclined at 30 degrees or less with respect to the axis, and wherein, between the first surface and the second surface, a twisted surface having a shape twisted with respect to an extending direction of the axis is formed, and the first surface and the second surface are connected by the twisted surface. a first surface disposed mostly in the first region and extending to be inclined from the inlet toward the outlet; and a second surface disposed mostly in the second region, the second surface is inclined to be away from the first surface as approaching the outlet, the second surface is inclined at 5 degrees or more with respect to the axis, and in the outlet, an area of a first portion included in the first region is smaller than an area of a second portion included in the second region, characterized in that: the second surface extends to be inclined from the inlet toward the outlet, the first surface is inclined at 5 degrees or less with respect to the axis, the second surface is inclined at 30 degrees or less with respect to the axis, and wherein, between the first surface and the second surface, a twisted surface having a shape twisted with respect to an extending direction of the axis is formed, and the first surface and the second surface are connected by the twisted surface. the second surface extends to be inclined from the inlet toward the outlet, the first surface is inclined at 5 degrees or less with respect to the axis, the second surface is inclined at 30 degrees or less with respect to the axis, and wherein, between the first surface and the second surface, a twisted surface having a shape twisted with respect to an extending direction of the axis is formed, and the first surface and the second surface are connected by the twisted surface.