A rocker bogie, comprising: a first base including a first wheel, a second wheel, and a third wheel each of which is configured to be in contact with a first flat surface; a second base including a fourth wheel which is configured to be in contact with the first flat surface; a rotary shaft connecting the first base and the second base to each other such that the second base is rotatable with respect to the first base; and a structure placed on the second base, wherein the rotary shaft is parallel to a first straight line which connects a rotation center of the first wheel and a rotation center of the second wheel to each other and is disposed between a rotation center of the third wheel and the first straight line, and wherein the fourth wheel is disposed at an opposite position to the third wheel across the first straight line, the rocker bogie being characterised in that: a center of gravity of the structure is positioned between the rotation center of the third wheel and the first straight line in a plan view, and in that when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the third wheel to the rotary shaft is defined as "b1", a distance from the first straight line to the rotary shaft is defined as "a", and a:b1 = 1:2 is satisfied, when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the fourth wheel to the first straight line is defined as "d1", a distance from a projected point of the center of gravity of the structure to a horizontal surface to a projected line of the rotary shaft to the horizontal surface is defined as "c", and c:d1 = 1:3 is satisfied. a first base including a first wheel, a second wheel, and a third wheel each of which is configured to be in contact with a first flat surface; a second base including a fourth wheel which is configured to be in contact with the first flat surface; a rotary shaft connecting the first base and the second base to each other such that the second base is rotatable with respect to the first base; and a structure placed on the second base, wherein the rotary shaft is parallel to a first straight line which connects a rotation center of the first wheel and a rotation center of the second wheel to each other and is disposed between a rotation center of the third wheel and the first straight line, and wherein the fourth wheel is disposed at an opposite position to the third wheel across the first straight line, the rocker bogie being characterised in that: a center of gravity of the structure is positioned between the rotation center of the third wheel and the first straight line in a plan view, and in that when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the third wheel to the rotary shaft is defined as "b1", a distance from the first straight line to the rotary shaft is defined as "a", and a:b1 = 1:2 is satisfied, when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the fourth wheel to the first straight line is defined as "d1", a distance from a projected point of the center of gravity of the structure to a horizontal surface to a projected line of the rotary shaft to the horizontal surface is defined as "c", and c:d1 = 1:3 is satisfied. when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the third wheel to the rotary shaft is defined as "b1", a distance from the first straight line to the rotary shaft is defined as "a", and a:b1 = 1:2 is satisfied, when viewed from the outside in a right-left direction, which is a direction parallel to an axle of the driving wheels, a distance from a ground contact position of the fourth wheel to the first straight line is defined as "d1", a distance from a projected point of the center of gravity of the structure to a horizontal surface to a projected line of the rotary shaft to the horizontal surface is defined as "c", and c:d1 = 1:3 is satisfied.