Multilayer substrate

A multilayer substrate comprising:

• an insulator including:
• a plurality of layers stacked on each other in a stacking direction;
• a first region;
• and
• a second region that is thinner than the first region in the stacking direction;
• a first signal line and a second signal line that are structured to extend across the first region and the second region and that overlap in a planar view in the stacking direction;
• and
• a first ground conductor and a second ground conductor that are provided on an outside of regions in which the first signal line and the second signal line are provided in the stacking direction;
• wherein
• in a region in which the first signal line and the second signal line face each other:
• a line width of the first signal line and a line width of the second signal line are smaller in the second region than in the first region;
• and
• a distance between the first signal line and the second signal line is smaller in the second region than in the first region;
• the first ground conductor overlaps with the first signal line and is closer to the first signal line than to the second signal line in the planar view in the stacking direction;
• the second ground conductor overlaps with the first signal line and is closer to the second signal line than to the first signal line in the planar view in the stacking direction;
• and
• the first signal line and the second signal line are provided between the first ground conductor and the second ground conductor in the stacking direction.