A silicon carbide semiconductor device, comprising: a silicon carbide layer of a first conductivity type; a silicon carbide layer of a second conductivity type formed on the silicon carbide layer of the first conductivity type; a gate trench formed to extend from a surface of the silicon carbide layer of the second conductivity type to such a depth that the gate trench reaches the silicon carbide layer of the first conductivity type; a gate electrode provided in the gate trench with an insulating film interposed therebetween; protection trenches formed to extend from the surface of the silicon carbide layer of the second conductivity type to a depth greater than the gate trench; a conductive member provided in the protection trenches; a cell region in a horizontal plane that includes both the gate trench and a protection trench that surrounds the gate trench with at least a part of the gate trench left unenclosed in the horizontal plane; and a gate region in the horizontal plane that includes a protection trench and in which a gate pad or a lead electrode connected to the gate pad is disposed, wherein the protection trench included in the cell region has a plurality of cell-region linear trench sections that extend straight in the horizontal plane, the protection trench included in the gate region has a plurality of sections (16, 17), and a minimum horizontal distance between opposed cell-region linear trench sections is greater than a maximum horizontal distance (D3, D4) between opposed sections (16, 17) of the protection trench included in the gate region, wherein, for each point of a section, a horizontal distance from that point to an opposed section is defined as the minimum distance from said point to the opposed section and wherein the minimum horizontal distance between opposed cell-region linear trench sections is the distance having the minimum value among all horizontal distances defined from all points of each section to the opposed section and wherein the maximum horizontal distance between opposed sections is the distance having the maximum value among all horizontal distances defined from all points of each section to the opposed section. a silicon carbide layer of a first conductivity type; a silicon carbide layer of a second conductivity type formed on the silicon carbide layer of the first conductivity type; a gate trench formed to extend from a surface of the silicon carbide layer of the second conductivity type to such a depth that the gate trench reaches the silicon carbide layer of the first conductivity type; a gate electrode provided in the gate trench with an insulating film interposed therebetween; protection trenches formed to extend from the surface of the silicon carbide layer of the second conductivity type to a depth greater than the gate trench; a conductive member provided in the protection trenches; a cell region in a horizontal plane that includes both the gate trench and a protection trench that surrounds the gate trench with at least a part of the gate trench left unenclosed in the horizontal plane; and a gate region in the horizontal plane that includes a protection trench and in which a gate pad or a lead electrode connected to the gate pad is disposed, wherein the protection trench included in the cell region has a plurality of cell-region linear trench sections that extend straight in the horizontal plane, the protection trench included in the gate region has a plurality of sections (16, 17), and a minimum horizontal distance between opposed cell-region linear trench sections is greater than a maximum horizontal distance (D3, D4) between opposed sections (16, 17) of the protection trench included in the gate region, wherein, for each point of a section, a horizontal distance from that point to an opposed section is defined as the minimum distance from said point to the opposed section and wherein the minimum horizontal distance between opposed cell-region linear trench sections is the distance having the minimum value among all horizontal distances defined from all points of each section to the opposed section and wherein the maximum horizontal distance between opposed sections is the distance having the maximum value among all horizontal distances defined from all points of each section to the opposed section.