A wireless module comprising: a substrate including a first main surface and a second main surface; a first ground pattern formed on the first main surface of the substrate and a second ground pattern formed on the second main surface of the substrate, the ground patterns being connected to each other; a heat generating component mounted on the first main surface of the substrate and connected to the first ground pattern; a pattern antenna including a grounding part connected to the first ground pattern and a power feeding part fed with power from the heat generating component, the pattern antenna being formed on the first main surface of the substrate; characterized in that the wireless module further comprises: a base plate electrically connected to the second ground pattern and disposed opposite to the pattern antenna, wherein the base plate has a shape in which a gap is formed between the second main surface and a portion of the base plate opposite to the pattern antenna, characterized in that: the base plate is connected to the second ground pattern by a conductive fastening member so as to form a connected portion, the connected portion being located on the second main surface directly opposite the location of the grounding part on the first main surface, or the connection portion being located on the second main surface adjacent the location directly opposite the location of the grounding part on the first main surface, the fastening member further connecting the base plate to the first ground pattern and to the grounding part, the connection with the grounding part being directly to the grounding part or to the first ground pattern at a distance to the grounding part 1/20 or less the wavelength of the electromagnetic wave used, wherein the base plate includes protrusions that make the contact with the second ground pattern. a substrate including a first main surface and a second main surface; a first ground pattern formed on the first main surface of the substrate and a second ground pattern formed on the second main surface of the substrate, the ground patterns being connected to each other; a heat generating component mounted on the first main surface of the substrate and connected to the first ground pattern; a pattern antenna including a grounding part connected to the first ground pattern and a power feeding part fed with power from the heat generating component, the pattern antenna being formed on the first main surface of the substrate; a base plate electrically connected to the second ground pattern and disposed opposite to the pattern antenna, wherein the base plate has a shape in which a gap is formed between the second main surface and a portion of the base plate opposite to the pattern antenna, characterized in that: the base plate is connected to the second ground pattern by a conductive fastening member so as to form a connected portion, the connected portion being located on the second main surface directly opposite the location of the grounding part on the first main surface, or the connection portion being located on the second main surface adjacent the location directly opposite the location of the grounding part on the first main surface, the fastening member further connecting the base plate to the first ground pattern and to the grounding part, the connection with the grounding part being directly to the grounding part or to the first ground pattern at a distance to the grounding part 1/20 or less the wavelength of the electromagnetic wave used, wherein the base plate includes protrusions that make the contact with the second ground pattern. the base plate is connected to the second ground pattern by a conductive fastening member so as to form a connected portion, the connected portion being located on the second main surface directly opposite the location of the grounding part on the first main surface, or the connection portion being located on the second main surface adjacent the location directly opposite the location of the grounding part on the first main surface, the fastening member further connecting the base plate to the first ground pattern and to the grounding part, the connection with the grounding part being directly to the grounding part or to the first ground pattern at a distance to the grounding part 1/20 or less the wavelength of the electromagnetic wave used, wherein the base plate includes protrusions that make the contact with the second ground pattern.