FIG. 10 is a characteristic diagram showing a result (1) of calculating the pass characteristic F and the reflection characteristic G of the high frequency filter 1 by means of an electromagnetic field analysis. Further, FIG. 11A is a table showing the sizes of the lands and the openings, and FIG. 11B is a table showing the spacings between the lands in different layers. The electromagnetic field analysis result (1) shown in FIG. 10 is calculated by defining the configuration of the high frequency filter 1 as follows. The sizes of the lands and openings of the high frequency filter 1 are determined to be values (in millimeters) described in the table (1) shown in FIG. 11A and the spacings between the lands are determined to be values (in millimeters) described in the table (2) shown in FIG. 11B in such a way that the capacitances C1, C2 and C3 shown in FIG. 6 are set, respectively, to 1.2 (pF), 2.6 (pF) and 1.2 (pF), each of the characteristic impedances Z of the connection portions 200 and 201 is 50 (Ω), each of the characteristic impedances Z of the coupled lines 202 and 203 is 67 (Ω), and each of the electrical lengths of these coupled lines is substantially 30 degrees at 6 (GHz) which is the cutoff frequency. The spacing dB between the inner conductor and the outer conductor which constitute the coaxial line 12B can be calculated in accordance with the following expression (3). For example, in the case where the diameter D of the columnar conductor 7 is 1 (mm), dB is 8.8 (mm). Here, εr is the dielectric constant of the dielectric substrate which constitutes the multilayer substrate 2.
