Abstract: A cleaning device includes: a plurality of rollers that hold a peripheral edge part of a substrate; a rotation driving unit that rotates the substrate by rotationally driving the plurality of rollers; a cleaning member that abuts on the substrate and cleans the substrate; a cleaning liquid supply nozzle that supplies a cleaning liquid to the substrate; a microphone that detects a sound generated when a notch of the peripheral edge part of the substrate hits the plurality of rollers; and a rotation speed calculation unit that calculates a rotation speed of the substrate on the basis of the sound detected by the microphone.

Abstract: A cleaning device includes: a plurality of rollers that hold a peripheral edge part of a substrate; a rotation driving unit that rotates the substrate by rotationally driving the plurality of rollers; a cleaning member that abuts on the substrate and cleans the substrate; a cleaning liquid supply nozzle that supplies a cleaning liquid to the substrate; a microphone that detects a sound generated when a notch of the peripheral edge part of the substrate hits the plurality of rollers; and a rotation speed calculation unit that calculates a rotation speed of the substrate on the basis of the sound detected by the microphone.

Abstract: A catalyzer-containing muffler for treating exhaust gas from an engine is disclosed. The muffler includes an outer casing defining a closed space therein and having an inlet pipe and an outlet pipe for introducing and discharging the exhaust gas into and out of the outer casing, respectively. At least one partition wall is provided so as to divide the closed space of the outer casing into two or more spaces. At least one penetration pipe is provided through each of the partition walls for placing the divided spaces in communication with each other, and a catalyzer is provided inside at least one of the penetrating pipes. Exhaust gas noise is thus reduced and at the same time toxic substances such as NO.sub.x or SO.sub.x are removed by the muffler by a single structure.

Abstract: A muffler is constructed to have a tubular perforated plate within its cavity so as to divide the cavity into an outer resonant cavity and an inner resonant cavity, to thereby provide two resonant frequencies. The tubular perforated plate is formed in the shape of a funnel.